Parasites Flashcards
1
Q
What are the main protozoa causes of GI infection?
A
Giardia lamblia
Entamoeba histolytica
Cryptosporidium
2
Q
How does Giardiasis present?
A
bloating, flautlence, foul-smelling fatty diarrhea (often seen in campers and hikers) and is transmitted via cysts in contaminated water
3
Q
How is Giardiasis tx?
A
metronidazole
4
Q
How is Giardiasis diagnosed?
A
Trophozoites or cysts in stool
5
Q
Entamoeba histolytics is the cause of _______
A
Amebiasis
6
Q
How does Amebiasis present?
A
bloody diarrhea (dysenery), liver abscess (anchovy oasta exudates), RUQ pain, and histology showing a flask-shaped ulcer
7
Q
How is Ambeiasis contracted?
A
cysts in water
8
Q
How is Amebiasis diagnosed?
A
Serology and/or trophozoites (With RBCs in the cytoplasm) or cysts (with up to 4 nuclei) in stool
9
Q
How is Amebiasis tx?
A
Metronidazole
iodoquinol for asymptomatic cyst passers
10
Q
What parasite is known to cause severe diarrhea in AIDs pts and mild disease (watery diarrhea) in immunocompetent hosts?
A
Cryptosporidium
11
Q
How is Cryptosporidium diagnosed?
A
oocysts on acid-fast stain
12
Q
How is Cryptosporidium tx?
A
prevention by filtering water supplies and nitazoxanide in immunocompetent hosts
13
Q
What protozoa cause CNS infection?
A
Toxoplasma gondii
Naegleria fowleri
Trypanosoma brucei
14
Q
What disease does Toxoplasma gondii cause?
A
1) Congenital toxoplasmosis with a classic triad of chorioretinitis (below), hydrocephalus, and intracranial calcifications
2) Reactivation in AIDs- ring enhancing lesions on CT/MRI
15
Q
Reactivation of Toxo in AIDs- ring enhancing lesions on CT/MRI
A
16
Q
How is toxo transmitted?
A
cysts in meat (most common); occysts in cat feces
crosses the placenta (pregnant women should avoid cats)
17
Q
How is toxo diagnosed?
A
Serology
or biopsy showing tachyzoites or bradyziotes
18
Q
How is toxo tx?
A
Sulfadiazine and pyrimethamine
19
Q
What disease does Naegleria fowleri cause?
A
Rapdily fatal meningoencephalitis
20
Q
How is Naegleria fowleri transmitted?
A
swimming in freshwater and enters via the cribriform plate
21
Q
How is Naegleria fowleri tx?
A
Ampho B (will likely die though)
22
Q
What parasite causes African Sleeping sickness?
A
Trypanosoma brucei
23
Q
How does African Sleeping sickness present?
A
enlarged lymph nodes, recurring fever due to antigenic variation, somnolence, and coma
24
Q
What is the reservoir of Trypanosoma brucei?
A
tsetse fly, a painful bite
25
How is Trypanosoma brucei diagnosed?
blood smear
26
How is African sleeping sickness tx?
Suramin for blood borne disease or melarsporol for CNS penetration
melatonin for sleep
27
What protozoa cause hematologic infections?
Plasmodium (P. viva.ovale, falcoparum, and malariae)
Babesia
28
Plasmodium is the cause of \_\_\_\_\_\_
Malaria
29
What are the primary symptoms of malaria?
fever, HA, anemia, and splenomegaly
30
What is the vector for Plasmodium?
Anopheles mosquito
31
How does P. vivax/ovale induced malaria present?
48 hr cycle (tertain; includes fever on first day and third dayl thus fevers are actually 48 hrs apart); dormant form (hypnozoite) in liver
32
How does P. falciparum induced malaria present?
severe; irregular fever pattern, parasitized RBCs occlude brain capillaries (cerebral malaria), kidneys, and lung
33
How does P. malariae induced malaria present?
72 hr cycle (quartan)
34
How is malaria diagnosed?
blood smear- trophzoite ring form within RBC (below)
Schizont containing merozoites
red granules (Schuffner stippling) throughout RBC cytoplasm seen with P. vivax/ovale
35
Malaria- Schizont containing merozoites
36
How is malaria tx?
Chloroquine for sensitive species (blocks Plsmodium heme polymerase)
If resistant, use mefloquine or atovaquone/proguanol
If life threatening, use IV quindine or artesunate (test for G6PD deficiency)
For P. vivax.ovale, add primaquine for hyponozoite (test for G6PD deficiency)
37
Babesia causes Babesiosis. How does this present?
fever and hemolytic anemia, predominantly i the northEASTERN US (asplenia increases the risk for disease)
38
What carriers Babesia?
Ixodes tick (same as Lyme disease- may often coinfect)
39
How is Babesia diagnosed?
blood smear (**ring form or Maltese cross**)
PCR
40
How is Babesia tx?
Atovaquone and azithromycin
41
What protozoa cause visceral infections?
Trypanosoma cruzi
Leishmania donovani
42
What disease does Trypanosoma cruzi cause?
Chagas disease
43
How does Chagas disease present?
dilated cardiomyopathy with apical atrophy
megacolon
megaesophagus
Romana sign- unilateral periorbital swelling (below)
mostly in South America
44
What transmits Trypanosoma cruzi?
reduviid bug (aka the kissing bug) which deposits it the parasite in feces or via a painless bite (like a kiss)
45
How is Chagas disease diagnosed?
Blood smear
46
47
How is Chaga disease tx?
Benznidazole or nifurtimox
48
What cause Visceral leishmaniasis?
Leishmania donovani
49
How does Visceral leishmaniasis present?
spikin fevers, hepatosplenomegaly, pancytopenia
50
What transmits Leischmania donovani?
sandflies
51
How is Leischmania donovani diagnosed?
Macrophages containg amastigotes
52
How is Leishmania tx?
Ampho B or sodium stibogluconate
53
What is the main sexually transmitted parasite?
Trichmonas vaginalis
54
What disease does Trichmonas vaginalis cause?
vaginitis, marked by a foul-smelling, greenish discharge, itching and burning (dont confuse with Gardnerella vaginalis, a gram-variable bacterium associated with bacterial vaginosis)
NOTE: This must be transmitted sexually because it cannot exist outside humans, cannot form cysts
55
How is vaginitis diagnosed?
Strawberry cervix
56
Vaginitis. Tx?
Metronidazole for pt and partner
57
What are the intestinal nematodes?
Enterbius vrmicularis (pinworm)
Ascaris lumbricoides (giant roundworm)
Strongyloides stercoralis
Ancylostoma duodenale, Necator americanus (hookworms)
Trichinella spiralis
58
How is Enterbius vrmicularis (pinworm) transmitted?
fecal-oral
59
How does Enterbius vrmicularis (pinworm) infection present?
intestinal infection causing anal pruritis, diagnosed by **seeing eggs via a tape test**
60
How is Enterbius vermicularis tx?
Bendazoles (because worms are bendy)
61
How is Ascaris lumbricoides transmitted and what disease does it cause?
fecal oral and causes an intestinal infection with possible obstruction of the ileocecal valve
62
How is Ascaris lumbricoides diagnosed?
visualizing eggs in feces
Tx: Bendazoles
63
How is Strongyloides stercoralis tx?
Larvae in the soil penetrate the skin
64
What disease does Strongyloides stercoralis cause?
Intestinal infection causing vomiting, diarrhea, epigastric pain (may feel like a peptic ulcer)
65
How is Strongyloides stercoralis tx?
Ivermectin or bendazoles
66
How is Ancylostoma duodenale, Necator americanus (hookworms) transmitted?
Larvae penetrating skin
67
What disease do Ancylostoma duodenale, Necator americanus (hookworms) cause?
intestinal infection causing ANEMIA by sucking blood from intestinal walls
68
How are hookworms tx?
bendazoles or pyrantel pamoate
69
How is Trichinella spiralis transmitted?
fecal- oral or undercooked meat (esp. pork)
70
What disease does Trichinella spiralis cause?
Intestinal infection; larvae enter the bloodstream and encyst in striated muscle cells causing **muscle inflammation**
Trichinosis- fever, vomiting, nausea, periorbital edema, myalgia
**It is sometimes referred to as the "pork worm" due to it being typically encountered in undercooked pork products.**
71
Trichinella species, the smallest nematode parasite of humans, have an unusual lifecycle, and are one of the most widespread and clinically important parasites in the world.[2] The small adult worms mature in the small intestine of a definitive host, such as a pig. Each adult female produces batches of live larvae, which bore through the intestinal wall, enter the blood (to feed on it) and lymphatic system, and are carried to striated muscle. Once in the muscle, they encyst, or become enclosed in a capsule. Humans can become infected by eating infected pork, horsemeat, or wild carnivores such as fox, cat, or bear
The first symptoms may appear between 12 hours and two days after ingestion of infected meat. The migration of adult worms in the intestinal epithelium can cause traumatic damage to the host tissue, and the waste products they excrete can provoke an immunological reaction. The resulting inflammation can cause symptoms such as nausea, vomiting, sweating, and diarrhea. Five to seven days after the appearance of these symptoms, facial edema and fever may occur. Ten days following ingestion, intense muscular pain, difficulty breathing, weakening of pulse and blood pressure, heart damage, and various nervous disorders may occur, eventually leading to death due to heart failure, respiratory complications, or kidney malfunction, all due to larval migration.
72
What parasites infect tissue?
Onchocerca volvulus
Loa loa
Wuchereria bancrofti
Toxocara canis
73
What is the carrier of Onchocerca volvulus?
female blackfly bite
74
How does Onchocerca volvulus infection present?
Hyperpigmented skin and river blindness (black flies, black skin nodules, "black" sight); allergic rxn to microfilaria possible
75
How is Onchocerca volvulus tx?
Ivermectin (for rIVER blindness)
76
What is the carrier of loa loa?
Deer fly, horse fly, **mango fly**
77
How does loa loa present?
worms in conjunctiva
swelling in skin
78
How is Loa Loa tx?
Diethylcarbamazine
79
What is the carrier of Wuchereria bancrofti?
Female mosquito
80
What disease does Wuchereria bancrofti cause?
Elephantiasis- due to worms blocking lymphatics (takes 9 months to a year to become symptomatic after a bite)
81
How is Wuchereria bancrofti tx?
Diethylcarbamazine
82
Toxocara canis
Transmission: fecal-oral
Disease: visceral larva migrans
Tx: Bendazoles
83
What nematodes cause disease via INGESTION?
Enterbius, Ascaris, Toxocara, Trichinella
## Footnote
**Youll get sick if you EATT these**
84
What nematodes cause disease CUTANEOUSLY?
Strongyloides, Ancylostroma, Necator
85
What nematodes cause disease via BITES?
Loa loa, Onchocerca volvulus, Wiuchereria bancrofti
86
What are the cestodes (tapeworms)?
Taenia solium
Diphyllbothrium latum
Echincoccus granulosus
87
Taenia solium can present two ways. Number 1.
Transmitted; Ingestion of larvae encysted in undercooked pork
Disease: intestinal infection
Tx: Praziquantel
88
Taenia solium can present two ways. Number 2.
transmission: Ingestion of eggs
Disease: **cysticercosis**, neurocysticercosis
Tx: Praziquantel; albenazole for neurocysticerosis
89
What is this?
neurocysticerosis via Taenia solium
90
How is Diphyllobothrium latum transmitted?
ingestion of larvae from raw freshwater fish
91
What disease does Diphyllobothrium latum cause?
vitB12 deficiency by competing for uptake (results in a megaloblastic anemia)
92
How is Diphyllobothrium latum tx?
Praziquantel
93
How is Echinococcus granulosus transmitted?
ingestion of eggs from dog feces
Sheep are an intermediate host
94
What disease does Echinococcus granulosus cause?
Hydatid cysts in the liver (below) causing anaphylaxis if antigens are releases (thus these hydatid cysts are injected with ethanol or hypertonic saline to kill daughter cysts before removal)
95
How is Echinococcus granulosus tx?
Albendazole
96
What are the termatodes (flukes)?
Schistosoma
Clonorchis sinesis
97
How is Schistosoma transmitted?
snails are the host and cercariae pentrate human skin
98
What disease does Schistosoma cause?
Liver and spleen enlargement leading to fibrosis and inflammation
99
Chronic infection with Schistosoma haemotobium can lead to what?
squamous cell carcinoma of the bladder (painless hematuria and pulmonary HTN)
100
How is Schistosoma tx?
Praziquantel
101
How is Clonorchis sinesis transmitted?
undercooked fish
102
What disease does Clonorchis sinesis cause?
bilitary tract inflammation causing pigmented gallstones; **associated with cholangiocarcinoma**
103
How is Clonorchis sinesis tx?
Praziquantel
